B1340

DTC B1340

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptors
DTC B1340 0B
- Device Power 3 Circuit Current Above Threshold

DTC B1340 42
- Device Power 3 Circuit Calibration Data Set Not Programmed

DTC B1340 4B
- Device Power 3 Circuit Calibration Not Learned




Diagnostic Fault Information






Circuit/System Description

The memory seat module (MSM) monitors the current supplied to driver and passenger seat lumbar vertical motors and both steering column actuators. The MSM can detect both absolute and differential current levels from the these motors. Absolute current is the maximum allowable current the module will supply to the motors. A differential current mismatch occurs when the current supplied to the motors does not match the current returning from the motors.


Conditions for Running the DTC

The seat lumbar motors or steering wheel actuators must be active.


Conditions for Setting the DTC

B1340 0B

The absolute current has exceeded the maximum value allowed.

B1340 42

This DTC will set if the module calibration is not programmed.

B1340 4B

This DTC will set if the module calibration is not learned.


Action Taken When the DTC Sets

All movement related to the seat lumbar motors and steering wheel actuators is aborted.


Conditions for Clearing the DTC

* The current DTC will clear and set the code to history, 3 seconds after no motor movement is requested or the current is no longer mismatched, and the power mode changes to OFF then back to ACC or RUN.
* The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.



Diagnostic Aids

The scan tool may reference the Memory Seat Module (MSM) as the Driver Position Module.


Reference Information
Schematic Reference

* Driver Seat Schematics (Driver Seat Schematics)
* Passenger Seat Schematics (Passenger Seat Schematics)

Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Memory Seats Description and Operation (Memory Seats Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Programming and Relearning (Programming and Relearning) for scan tool information


Circuit/System Testing


B1340 0B
1. Use a scan tool to clear the current and history diagnostic trouble code.
2. Ignition ON, determine which motor set this DTC by operating the motors listed below one at a time in both directions. Check for the DTC to set between each motor test.

* Driver Seat Lumbar Vertical Motor
* Passenger Seat Lumbar Vertical Motor
* Steering Column Tilt Actuator
* Steering Column Telescope Actuator

3. Use a scan tool to clear the current and history diagnostic trouble code.
4. Ignition OFF, disconnect the harness connector at the motor/actuator for which the DTC set.
5. Ignition ON, operate the motor/actuator in both directions then verify that the DTC set.

• If the DTC did not set, test or replace the motor/actuator .

6. Ignition OFF, disconnect the appropriate X1 or X4 harness connector at the memory seat module.
7. Ignition ON, test for 0 volts between the appropriate control circuit terminals listed below and ground.

* Driver Seat Lumbar Vertical Motor terminals 1 and 2 X4
* Passenger Seat Lumbar Vertical Motor terminals 4 and 5 X4
* Steering Column Tilt Actuator terminals 7 and 8 X4
* Steering Column Telescope Actuator terminals 7 and 8 X1


• If greater than the specified value, test the control circuit for a short to voltage.

8. Test for infinite resistance between each control circuit and ground.

• If not the specified value, test the control circuit for a short to ground.

9. Test for infinite resistance between the control circuits.

• If not the specified value, test for a short between the control circuits.

10. If all circuits test normal, test or replace the memory seat module.


B1340 42 or B1340 4B

If either DTC is set history or current, replace the MSM.


Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Front Seat Lumbar Support Replacement (w/AM3) (Front Seat Lumbar Support Replacement (w/AM3))Front Seat Lumbar Support Replacement (w/AL2) (Front Seat Lumbar Support Replacement (w/AL2))
* Tilt Motor Replacement (Service and Repair)
* Telescope Actuator Assembly Replacement (Telescope Actuator Assembly Replacement)
* Programming and Relearning (Programming and Relearning) for MSM replacement, programming and setup